U.S. patent application number 11/052086 was filed with the patent office on 2005-08-18 for simplified capacitive touchpad and method thereof.
Invention is credited to Chien, Yung-Lieh, Chiu, Yen-Chang, Tang, Cheng-Hao.
Application Number | 20050179672 11/052086 |
Document ID | / |
Family ID | 34836994 |
Filed Date | 2005-08-18 |
United States Patent
Application |
20050179672 |
Kind Code |
A1 |
Chiu, Yen-Chang ; et
al. |
August 18, 2005 |
Simplified capacitive touchpad and method thereof
Abstract
In a capacitive touchpad, a plurality of sensing zones are
defined, and a controller is connected with a plurality of scan
lines for sensing a movement of an object slipping on the plurality
of sensing zones, wherein at least one of the plurality of scan
lines is connected to at least two of the plurality of sensing
zones. The distance, speed and direction of the movement are
determined by detecting the object on the touchpad at two positions
upon two scans, and thereby the control of a scroll bar is
accomplished. The capacitive touchpad is applied for a Z-axis
arrangement on a mouse and a scroll arrangement on a keyboard.
Inventors: |
Chiu, Yen-Chang; (Taipei
County, TW) ; Chien, Yung-Lieh; (Taoyuan City,
TW) ; Tang, Cheng-Hao; (Tucheng City, TW) |
Correspondence
Address: |
ROSENBERG, KLEIN & LEE
3458 ELLICOTT CENTER DRIVE-SUITE 101
ELLICOTT CITY
MD
21043
US
|
Family ID: |
34836994 |
Appl. No.: |
11/052086 |
Filed: |
February 8, 2005 |
Current U.S.
Class: |
345/173 |
Current CPC
Class: |
H03K 17/9622 20130101;
G06F 3/03543 20130101; G06F 3/0213 20130101; H03K 2217/96066
20130101; G06F 3/03547 20130101; G06F 2203/0339 20130101; G06F
3/0446 20190501 |
Class at
Publication: |
345/173 |
International
Class: |
G09G 005/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 17, 2004 |
TW |
093103816 |
Claims
What is claimed is:
1. A simplified capacitive touchpad comprising: a plurality of
sensing zones; a plurality of scan lines for scanning the plurality
of sensing zones; and a controller connected with the plurality of
scan lines for sensing a movement of an object slipping on the
plurality of sensing zones; wherein at least one of the plurality
of scan lines is connected to at least two of the plurality of
sensing zones.
2. The touchpad of claim 1, wherein the plurality of sensing zones
have a substantially same area.
3. The touchpad of claim 1, wherein the plurality of sensing zones
have a same number of traces.
4. The touchpad of claim 1, wherein at least two of the sensing
zones have different numbers of traces.
5. A method for sensing a movement of an object slipping on a
capacitive touchpad, the method comprising the steps of: defining a
plurality of sensing zones on the touchpad; connecting a plurality
of scan lines to the touchpad with at least one of the plurality of
scan lines connected to at least two of the plurality of sensing
zones; scanning the plurality of sensing zones by the plurality of
scan lines for detecting the object on the touchpad at a first
position upon a first scan and at a second position upon a second
scan; and determining a distance and a direction of the movement
from the first and second positions.
6. The method of claim 5, further comprising initializing an
automatic scroll function upon the first or second position at a
top end or a bottom end of the touchpad.
7. The method of claim 5, further comprising determining a speed of
the movement from a time interval and the distance between the
first and second positions.
8. The method of claim 5, further comprising performing a scroll
bar control upon the distance and direction of the movement.
9. A capacitive touchpad for a Z-axis arrangement on a mouse, the
touchpad comprising: a plurality of sensing zones; a plurality of
scan lines for scanning the plurality of sensing zones; and a
controller connected with the plurality of scan lines for sensing a
movement of an object slipping on the plurality of sensing zones,
and performing a scroll function including scrolling on a window
upon a distance and direction of the movement or determining a
scroll acceleration on the window upon a speed of the movement;
wherein at least one of the plurality of scan lines is connected to
at least two of the plurality of sensing zones.
10. The touchpad of claim 9, wherein the plurality of sensing zones
have a substantially same area.
11. The touchpad of claim 9, wherein the plurality of sensing zones
have a same number of traces.
12. The touchpad of claim 9, wherein at least two of the sensing
zones have different numbers of traces.
13. A capacitive touchpad for a scroll arrangement on a keyboard,
the touchpad comprising: a plurality of sensing zones; a plurality
of scan lines for scanning the plurality of sensing zones; and a
controller connected with the plurality of scan lines for sensing a
movement of an object slipping on the plurality of sensing zones,
and performing a scroll function including scrolling on a window
upon a distance and direction of the movement or determining a
scroll acceleration on the window upon a speed of the movement;
wherein at least one of the plurality of scan lines is connected to
at least two of the plurality of sensing zones.
14. The touchpad of claim 13, wherein the plurality of sensing
zones have a substantially same area.
15. The touchpad of claim 13, wherein the plurality of sensing
zones have a same number of traces.
16. The touchpad of claim 13, wherein at least two of the sensing
zones have different numbers of traces.
17. A simplified capacitive touchpad comprising: a plurality of
sensing zones in a first and second directions; a first group of
scan lines for scanning the plurality of sensing zones in the first
direction; a second group of scan lines for scanning the plurality
of sensing zones in the second direction; and a controller
connected with the first and second groups of scan lines for
sensing a movement of an object slipping on the plurality of
sensing zones in the first or second directions; wherein at least
one of the plurality of scan lines is connected to at least two of
the plurality of sensing zones.
18. The touchpad of claim 17, wherein the plurality of sensing
zones have a substantially same area.
19. The touchpad of claim 17, wherein the plurality of sensing
zones have a same number of traces.
20. The touchpad of claim 17, wherein at least two of the sensing
zones in the first or second directions have different numbers of
traces.
Description
FIELD OF THE INVENTION
[0001] The present invention is related generally to a capacitive
touchpad, and more particularly, to a capacitive touchpad with
reduced scan lines and a method for the touchpad.
BACKGROUND OF THE INVENTION
[0002] Capacitive touchpad is widely used for the pointing device
in a computer system. A capacitive touchpad typically has a large
number of scan lines connected from the controller chip of the
touchpad to a group of X trances and a group of Y trances that are
arranged to have a matrix of intersections each between one X trace
and one Y trace, and detects the position on a panel of the
touchpad that is touched by an object such as finger or conductor
by detecting the capacitance change at the intersection
corresponding to the touched position. The conventional capacitive
touchpad could further determine the distance and speed of a
movement of the object slipping on the panel upon the variations of
the touched position.
[0003] To connect with scan lines, the controller chip of a
conventional capacitive touchpad is requested to have a large
number of pins each for one of the scan lines. In other words, the
number of the pins for the scan lines is the same as the number of
the scan lines. As the number of the scan lines increases, the
number of the pins on a controller chip of a conventional
capacitive touchpad increases accordingly, and the related circuit
in the controller is also enlarged. As a result, the chip size and
the cost of the fabrication as well as the package for the
controller chip increase. Moreover, in the operations of a
capacitive touchpad, the more the scan lines the touchpad has, the
more power the controller thereof consumes.
[0004] Therefore, it is desired a simplified capacitive touchpad
with lower cost and power consumption.
SUMMARY OF THE INVENTION
[0005] One object of the present invention is to provide a
simplified capacitive touchpad with reduced amount of scanning work
thereof.
[0006] Another object of the present invention is to provide a
novel application of a capacitive touchpad that detects a movement
in one or more directions, rather than the exact position of a
touch on the panel of the touchpad.
[0007] A capacitive touchpad according to the present invention
comprises a plurality of sensing zones, a plurality of scan lines
for scanning the plurality of sensing zones, and a controller
connected with the plurality of scan lines for sensing a movement
of an object slipping on the plurality of sensing zones, wherein at
least one of the plurality of scan lines is connected to at least
two of the plurality of sensing zones. The method for sensing the
movement of the object slipping on the touchpad comprises detecting
the object on the touchpad at a first position during a first scan
and at a second position during a second scan to determine a
distance and direction of the movement. Alternatively, the
controller further determines a speed of the movement from the time
interval and distance between the first and second positions.
[0008] The capacitive touchpad is applied for a Z-axis arrangement
on a mouse and a scroll arrangement on a keyboard.
BRIEF DESCRIPTION OF DRAWINGS
[0009] These and other objects, features and advantages of the
present invention will become apparent to those skilled in the art
upon consideration of the following description of the preferred
embodiments of the present invention taken in conjunction with the
accompanying drawings, in which:
[0010] FIG. 1 shows an illustrative diagram of a capacitive
touchpad according to the present invention;
[0011] FIG. 2 shows an illustrative diagram of a mouse that has a
Z-axis arrangement employing the touchpad shown in FIG. 1;
[0012] FIG. 3 shows an illustrative diagram of a keyboard that has
a scroll arrangement employing the touchpad shown in FIG. 1;
[0013] FIG. 4A shows an illustrative diagram of a window that is
scrolled by the touchpad shown in FIG. 1;
[0014] FIGS. 4B to 4G show several illustrative waveforms upon a
finger slipping on the touchpad shown in FIG. 1 to scroll the
window shown in FIG. 4A; and
[0015] FIG. 5 shows an illustrative diagram of another capacitive
touchpad according to the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0016] FIG. 1 shows an illustrative diagram of a capacitive
touchpad according to the present invention, in which it is defined
two sensing zones 10 and 12 each having 4 traces, a group of scan
lines 14 includes 4 scan lines 140, 142, 144 and 146 each connected
to one trace of the sensing zone 10 and one trace of the sensing
zone 12 for scanning the sensing zones 10 and 12, and a controller
16 is connected with the scan lines 140, 142, 144 and 146 for
sensing a movement of an object such as finger or conductor
slipping on the sensing zones 10 and 12. Alternatively, depending
on the specific applications, a capacitive touchpad according to
the present invention may have more sensing zones, and the sensing
zones may have a same area or different areas, and a same number of
scan lines or different numbers of scan lines. In one embodiment, a
touchpad comprises at least a sensing zone whose traces are more
than those of the other sensing zones, and the group of scan lines
includes at least one scan line not connected to all of the sensing
zones. Referring to FIG. 1, since the sensing zones 10 and 12 are
connected in parallel to the controller 16 by the group of scan
lines 14, the controller 16 could scan the sensing zones 10 and 12
simultaneously by the scan lines 140, 142, 144 and 146. The
capacitive touchpad may be applied for a Z-axis arrangement on a
mouse and a scroll arrangement on a keyboard, to determine the
distance, direction and speed of the movement on the touchpad, and
to thereby provide a scroll function by the distance and direction
of the movement, as well as determine the scroll acceleration by
the distance and speed of the movement. As shown in FIG. 1, the
direction of a movement on the touchpad may be an upward direction
18 or a downward direction 20, and the top end 22 of the sensing
zone 10 and the bottom end 24 of the sensing zone 12 may be in
correspondence with the upper and lower edges respectively, of a
scroll bar on a window. If a touchpad has more sensing zones that
are connected in parallel to the controller of the touchpad by a
group of scan lines, the area for the finger to slip thereon to
control the scroll bar on a window will be enlarged.
[0017] Two applications of the touchpad shown in FIG. 1 are
illustrated by FIG. 2 and FIG. 3. In FIG. 2, a mouse 30 has a
Z-axis arrangement 32 that employs the touchpad as the interface
operated by users to control the scroll bar on a window. In FIG. 3,
a keyboard 40 has a scroll arrangement 42 that employs the touchpad
as the interface operated by users to control the scroll bar on a
window. Briefly, the touchpad on the mouse 30 or on the keyboard 40
represents a scroll bar on the window that is operated on a
computer system having the mouse 30 or the keyboard 40 as its
peripheral. In association with a detection method carried out by
the touchpad, the distance, direction and speed of a movement of a
finger slipping on the touchpad are determined by two positions of
the finger and the time interval between the two positions that are
detected. The scrolling direction and amount of the scroll bar on a
window could be determined by the direction and distance of the
movement of the finger slipping on the touchpad, and the scrolling
acceleration of the scroll bar on the window could be determined by
the speed of the movement.
[0018] Referring to FIG. 1, in this embodiment, there are 8 traces
in total arranged for a one-directional scroll bar and for two
defined sensing zones 10 and 12, and therefore, only four scan
lines 140, 142, 144 and 146 are required to sense the sensing zones
10 and 12 by each scan line connected to both of the sensing zones
10 and 12. To scan the sensing zones 10 and 12, it is scanned in
turn by the pairs of scan lines 140 and 142, 142 and 144, 144 and
146, as well as 146 and 140, each time one pair of scan lines to
sense the sensing zones 10 and 12 simultaneously. In one scan
cycle, four scans are performed to completely sense the sensing
zones 10 and 12 once by the four pairs of scan lines each for one
scan. Subsequently, the position where a finger touches is
determined during each scan cycle, and the distance, speed and
direction of the movement of the finger slipping on the sensing
zones 10 and 12 are determined by two detected positions of two
scan cycles. Moreover, if the finger is detected at the upper end
22 of the touchpad, an automatic scroll-up function is initialized,
and if the finger is detected at the lower end 24 of the touchpad,
an automatic scroll-down function is initialized.
[0019] FIG. 4A shows an illustrative diagram of a window that is
operated by the touchpad shown in FIG. 1. In a window 50, the
touchpad could directly control the scroll bar 52 on the window 50
to scroll the window 50 upward and downward, without moving the
curser on the scroll bar 52 in advance. When a finger is slipping
on the sensing zones 10 and 12 to scroll the window 50, several
exemplary waveforms are illustrated in FIGS. 4B to 4G for various
positions of the finger.
[0020] In FIG. 4B, the finger touches at the upper end 22 of the
touchpad, and a waveform 102 is produced accordingly. The position
100 of the finger is thus determined by the controller 16 upon the
waveform 102, and the automatic scroll-up function could be further
initialized by the controller 16.
[0021] When the finger is slipping on the sensing zone 10, FIG. 4C
shows the detected waveforms. The position 150 produces the
waveform 152, and when the finger moves to the position 154,
waveform 156 is produced. If the finger moves downward from the
position 150 to position 158, waveform 160 is produced. Based on
the waveforms 152 and 156, or 152 and 160, obtained from two scan
cycles, the controller 16 may determine the distance and direction
of the movement of the finger, and further control the scroll bar
52. In particular, if the waveforms 152 and 156 are detected from
two scan cycles, the finger is determined to slip upward, and the
automatic scroll-up function is initialized. On the contrary, if
the waveforms 152 and 160 are detected from two scan cycles, the
finger is determined to slip downward, and the automatic
scroll-down function is initialized. From the distance and time
interval between the two detected positions, the speed of the
movement may be further obtained, and the controller 16 could
further determine the scroll acceleration of the scroll bar.
[0022] FIGS. 4D and 4E show the waveforms when the finger is
slipping across the boundary between the sensing zones 10 and 12.
As shown in FIG. 4D, the position 200 produces the waveform 202,
and when the finger moves upward to the position 204, waveform 206
is produced. Based on the waveforms 202 and 206 obtained from two
scan cycles, the controller 16 may determine the finger moves
upward from the position 200 to the position 204 and the distance
of the movement, and further initialize the automatic scroll-up
function. In FIG. 4E, two positions 200 and 208 are determined by
two detected waveforms 202 and 210 from two scan cycles, and
accordingly, the controller 16 may determine the finger moves
downward from the position 200 to the position 208 and the distance
of the movement, and further initialize the automatic scroll-down
function.
[0023] FIG. 4F shows the detected waveforms when the finger is
slipping on the sensing zone 12. The position 250 produces the
waveform 252. If the finger moves upward to the position 254,
waveform 256 is produced. Alternatively, when the finger moves
downward to the position 258, waveform 260 is produced. Based on
the waveforms 252 and 256, or 252 and 260, obtained from two scan
cycles, the controller 16 may determine the distance and direction
of the movement of the finger, and further control the scroll bar
52. If the waveforms 252 and 256 are detected from two scan cycles,
the finger is determined to slip upward, and the automatic
scroll-up function is initialized, while if the waveforms 252 and
260 are detected from two scan cycles, the finger is determined to
slip downward, and the automatic scroll-down function is
initialized. From the distance and time interval between the two
detected positions, the speed of the movement may be further
obtained, and the controller 16 could further determine the scroll
acceleration of the scroll bar.
[0024] In FIG. 4G, the position 300 the finger touches is at the
lower end 24 of the touchpad, and it produces the waveform 302. The
controller 16 may determine the finger at the lower end 24 of the
touchpad upon the waveform 302, and initializes the automatic
scroll-down function.
[0025] FIG. 5 shows an illustrative diagram of another capacitive
touchpad according to the present invention. The touchpad of this
embodiment allows the detection of a movement in X and Y
directions. Sensing zones 350 and 352 are defined for the
X-direction, and sensing zones 354 and 356 are defined for the
Y-direction. In the group of scan lines 358 for the detection of a
movement in the X direction, each of scan lines 3580, 3582, 3584
and 3586 is connected to both of the sensing zones 350 and 352.
Likewise, in the group of scan lines 360 for the detection of a
movement in the Y direction, each of scan lines 3600, 3602, 3604
and 3606 is connected to both of the sensing zones 354 and 356.
There are sixteen traces, i.e., eight X traces and eight Y traces,
in this embodiment, but only eight scan lines are provided. In
other words, the number of the scan lines is one half of that of
the traces. In other embodiments, depending on the specific
applications, a capacitive touchpad may have more sensing zones in
either one or both of the X and Y directions, and the sensing zones
may have a same area or different areas. Furthermore, the numbers
of the scan lines for the X and Y directions may be same or
different, and the sensing zones may have a same area or different
areas. In yet other embodiments, there is at least one scan line
not connected to all the sensing zones in the X direction or in the
Y direction. A controller 362 is connected with the groups of scan
lines 358 and 360, to detect the sensing zones 350 and 352
simultaneously by the scan lines 3580, 3582, 3584 and 3586, and to
detect the sensing zones 354 and 356 simultaneously by the scan
lines 3600, 3602, 3604 and 3606. When this touchpad is applied for
a Z-axis arrangement on a mouse or a scroll arrangement on a
keyboard, it is capable of providing the direct control of a
vertical scroll bar and a horizontal scroll bar, by determining the
distance, speed and direction of a movement of an object slipping
on the touchpad in both the X and Y directions.
[0026] While the present invention has been described in
conjunction with preferred embodiments thereof, it is evident that
many alternatives, modifications and variations will be apparent to
those skilled in the art. Accordingly, it is intended to embrace
all such alternatives, modifications and variations that fall
within the spirit and scope thereof as set forth in the appended
claims.
* * * * *